Abstract Our recently completed R01 suggested that processing speed and attention (PS/A) oriented cognitive training (VSOP) produced robust effect on PS/A and working memory, but not in cognitive control or episodic memory, and long-term effects were overall modest. In the proposed R01 renewal, we propose to identify additional attributes to further enhance transferred and long-term effects of PS/A training in older adults with amnestic mild cognitive impairment (MCI) by addressing adaptation capacity that underpins adaptive learning and neuroplasticity. The goal of the stage II double-blinded randomized trial is to test whether adding resonance frequency breathing (RFB) training to VSOP will strengthen multiple contributors to adaptation capacity, particularly the central and peripheral pathways of autonomic nervous system (ANS) flexibility, which will strengthen VSOP training effect on cognitive and brain function and slow the progress of dementia in MCI. Our central hypothesis is that strengthening adaptation capacity, via improving autonomic nervous system (ANS) flexibility, will enhance neuroplasticity and slow progress of dementia in MCI, since adaptation capacity is critical for neuroplasticity of VSOP, but compromised in neurodegenerative process. Older adults with MCI (n = 114) will be randomly assigned to an 8-week combined intervention (RFB+VSOP), VSOP with guided imagery relaxation (IR) control, and a waitlist IR control, with periodical booster training sessions at follow-ups. Mechanistic and distal outcomes include ANS flexibility and multiple markers of dementia progress. Data will be collected across a 14-month period. The two primary aims are to examine long-term effects of the combined intervention on ANS flexibility (Aim 1), as well as the cognitive, behavioral, and functional capacity (Aim 2). The exploratory aim will be to determine the preliminary long-term effect of the combined intervention on neurodegeneration. We consider this a reasonable renewal plan from our completed R01, aiming to identify additional attributes to further enhance transferred and long-term effects of cognitive training in MCI. This will be among the first RCTs to examine a novel, combined intervention targeting adaptation capacity in MCI, with an ultimate goal for slowing neurodegeneration. The proposed work is aligned with NINR strategic plan to advance nursing science, eps. symptoms management (in this case, improving cognitive and functional symptoms in MCI) using a non-pharmacological intervention approach and understanding relevant mechanisms.